Boiler plug



y 22, 1924. v E. KEY

B ER PLUG Filed April 1, 1920 1 "Ki/r i J J w Patented July 22, 1924.

,y 1,502,038 PATENT OFFICE- FREDERICK E. KEY, OF 8'1. LOUIS, MISSOURI, ASSIGNOR TO KEY BOILER EQUIPMENT COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF: MISSOURI.

1:01pm PLUG.

Application filed April 1,1920. Serial No. 870,640.

To all whom it may concern:

Be it known that I, FREDERICK E. KEY, a citizen of the United States of America, a resident of the cit of St. Louis, the 5 State of Missouri, ave invented certain new and useful Improvements in Boiler Plugs, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming 9. art of this specification.

his invention relates to improvements in boiler plugs, the main object being to produce a highly etficient means for form- 1ng an absolutely tight seal at the opening to be closed. Another ob'ect is to roduce a plug of this kind whic is not liable to be unseated by the pressure in the boiler. A further object is to provide an efficient boiler plug havin a number of different elements, all of w ich can be very easily ap lied to and removed from a boiler.

ith the foregoing and other objects in view, the invention comprises the novel construction, combination and arrangement of parts hereinafter more specifically described and illustrated in the accompanying drawings wherein is shown the preferred embodiment of the invention. However, it is to be understood that th invention comprehends changes, variations and modifications which come within the scope of the claims hereunto appended.

Fig. I is an elevation showing the inner face of a boiler wall and the inner end of the plug. I

Fig. II is a Vertical section of the elements shown in Fi I.

Fig. III is a section on the line III-III,

Fig. II.

4o ig. IV is a detail view suggesting the manner in which the spreader can be inserted from the outside of the boiler.

1 designates a boiler wall provided with a hole 2 adapted to be closed by my boiler plug. To illustrate the preferred form of the invention I have shown a plug, or closure, consisting of four different elements, viz, a spreader A, a thrust member in the form of a ring B, a sealing ring C, and a so nut D.

The spreader A is provided with a taper face 3 which lies within the hole 2 so as to be engaged by the inner margin of the sealing ring C. Oppositely disposed flanges 4,

6t extending from the spreader, lie within the boiler and engage the inner face of the boiler wall as shown in Fi II. A stud 5 extends outwardly from t e spreader A, and 1t 1s preferably formed integral with the spreader.

The outer end of the sealing ring C is engaged by the thrust ring B, while the inner margin of the sealing ring lies entirely within the hole 2, where it is interposed between and in contact with the face of the hole and the tapered portion of the spreader. By referring to Fig. II it will be seen that the nut D may be tightened on stud 5 with the result of forclng thrust member B toward the spreader wall. vWhen this occurs, the sealin ring C will be firmly forced onto tapered ace 30f the spreader, whereby the inner mar in of the sealing ring is expanded slight y and forced into contact with the face of thehole in the boiler. The sealing ring, which is made of relatively soft metal such as soft steel, is thus expanded on the tapered face of the spreader and at the same time firmly seated against the face of the hole in the boiler so as to form an absolutely tight and leakproof seal. The wedging action at the inner margin of the sealing ring compensates for any slight depressions, or irregularities, which are usually found in the face of the hole or in the tapered face of the spreader.

In tightening the nut D, the thrust ring B will tend to turn with the nut, and a movement of this kind is undesirable, for the thrust ring should not imgart rotary motion to the sealin ring and thespreader A should not he permitted to turn with the nut D. Any suitable means may be employed to prevent independent rotation of the spreader A and thrust ring B, for example, the stud 5 may be provided with a non-circular portion 5' and the thrust member B may be provided with a noncircular hole '5 (Fig. III) adapted to receive said non-circular ortion. The thrust member is thus slidabl mounted on the stud 5 and interlocked t erewith to revent independent rotation of the sprea er and thrust member. The thrust member B may be provided with, flat faces 6, as shown 1n Fig. III adapted to receive a wrench, whereby the thrust member may be held-while the nut D is tightened.

All of the parts can be applied and removed from the outside of the boiler. The no tlan es 4 on spreader A will pass through the ole when the spreader is tilted and roperl manipulated as suggested by F V, and allthe other arts are very easi y ap lied from the outsi e of the bo ler.

he inner margin of seal ng ring C 15 very firmly wedged between the tapered outer face of the s reader and the inner face of the hole. T is feature is quite important, for it enables a very tight seal to be produced at the inner end of the sealing ring, and at the same time enables the sealin ring to be easily removed from the boiler. If the inner margin of the sealing ring were not located entirely within the hole, in other words, if the ring passed entirely through the hole and extended from the inner face of the boiler, said sealing ring would be mutilated by the expand n operation and it would be extremel di cult to remove. said ring. A highly e cient seal is obtained by the new combinationland airrangement of elements, and all of the elements, including the sealing ring, can be very easily removed from the outside of the boiler.

The hole 2 in the boiler wall is preferably tapered as shown in Fig. H, to permit free remova of the sealing ring 0. The tapered face 3 of the spreader lies at an angle to the tapered face of the hole to provide converging faces between which the sealing r ng is wedged in such a manner that it can be afterward easily withdrawn from the hole.

The sealing ring 6 can be re-used a number of times, for it is not mutilated or destroyed by the operation whereby it is tightened 1n the hole, nor by the operation of removing the ring from the hole.

The seal is formed at the inner margin of the sealin ring, and the inner end of this ring is su jected to the boiler ressure, but this pressure cannot displace t e ring. Instead of rel ing upon frictional; the inner margin of the ring to prevent displacement thereof, the sealing ring is positively anchored in the following manner. The flanges 4 on the spreader A cooperate with the inner face of the boiler wall to prevent outward displacement of the spreader, and since the stud 5 is formed integral with the spreader, the thrust member B will cooperate with nut D to prevent outward displacement of the sealing rin 0. Therefore, the flanges 4-. cooperate wit other elements of the combination to positively prevent outward displacement of sealin ring C when the latter is subjected to the oiler pressure.

In tightening the nut 11), the spreader A is held in a fixed position by its flanges t which then engage the inner face of the boiler wall, while the thrust member l3 is forced toward the boiler wall for the purpose of wedging the inner margin of ring 0 into frictional contact" with the face of the hole.

' aeeaose wall to receive the thrust member B which is separated from the-outer face of said wall.

The thrust member 18 is preferably recessed to receive and closely confine the extended outer margin of the sealin rin said thrust member havin an annu ar ange 7 surrounding and c osely fitted to said extended outer margin. The flange 7 cooperates with the sealing ring C to locate and retain the several elements in their proper relative positions during the period immediately before the tightening of the sealing rin so when the sealing ring contacts with t e ta ered faces 2 and 3,. the axis of said ring will lie parallel with the axis of the hole. The flan e 4 also serves as a reinforcing element for the outer margin of the sealing ring C.

I claim:

1. In a closure for tapered holes in boiler walls, a tapered spreader comprising a head having a tapered portion located within the hole to be closed, the largest diameter of said tapered portion being smaller than the diameter of the hole, said spreader also having flanges adapted to pass throu h the hole and engage the inner face of t e boiler wall to prevent outward displacement of the spreader, the spreader ta er being at an angle tothe tapered face of t e hole so as to provide the converging faces, a sealing ring having its inner mar in entirely within the hole to be closed, sai inner margin being interposed between and in contact with said converging faces of the hole and spreader, the outer margin of said sealing ring being extended from the wall of the boiler, a thrust member seated on the outer edge of said sealing ring and provided with an annular reinforcing flange overlapping and closely fitted to the extended outer margin of the sealing ring, a screw threaded stud formed integral with and extending outwardly from said spreader, the periphe of said spreader being so small that the spreader can be tilted and inserted through the hole without displacing the screw threaded stud relative to the spreader, said stud having a non-circular portion and said thrust member being slidably mounted thereon to prevent independent rotation of said thrust member and spreader, and a nut on said stud, said thrust member being movable toward the wall of the boiler in response to rotation of the nut so as to force said inner margin of the sealing ring into firm contact with said converging faces.

2. In a closure for holes in boiler walls, a tapered spreader comprising a head having a tapered portion locatedwithin the hole to he closed, the largest diameter of said tapered portion being smaller than the diameter of llt) lld

the hole, said spreader also having flanges adapted to pass throu h the hole and engage the inner face of the ioiler wall to revent outward displacement of thesprea er, the spreader taper being at an an is to the face of the hole so as to provide t 1e converging faces, a sealing ring having its inner margin entirely within. the hole to be closed, said 1nner margin being interposed between and in contact with said converging faces of the hole and spreader, the outer margin of said.

sealin ring being extended from the wall of the boiler, a stud rigid with and extending outwardly from said spreader, the periphery of said spreader being so small that the spreader can be tilted and inserted through the hole withoutdisplacing the spreader relative to the rigid stud, a thrust member slidably mounted on said stud and engagin said seal inga'ing, and a nut. mounted on sai stud and engaging said thrust member, said thrust member being rovided with an annularrecess into whic 1 the outer portion of said sealing ring extends, a wallof said recess overlapping the outer peripheral face of said sealing ring and being closely fitted to said outer peripheral face of said sealing ring so as 'to aline the sealing ring with the spreader.

hereunto aflix my signature.

FREDERICK E. KEY.

In testimony that I claim the foregoing 

